JPH0321178Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a charging circuit, and more particularly to a charging circuit for a small electric appliance that switches between two sets of rechargeable batteries, a main and an auxiliary battery, each having a different capacity.

In general, rechargeable small electric devices have the advantage of being easy to supply power and can be used anywhere.
There is a limit to the amount of electricity that can be supplied with a single charge, and users often continue using the device without knowing that the battery is about to run out, which could cause the device to stop mid-use.

To solve the above problem, in addition to the conventional main battery, a small auxiliary battery with a smaller capacity than the main battery is built in at the same time, and when the main battery is confirmed to be dead, the power source is switched to the auxiliary battery and it can be used. Attempts have been made to prevent equipment from becoming unusable during the process.

However, although incorporating an auxiliary battery in addition to the main battery leads to an increase in volume, if you try to charge the auxiliary battery at the same time as the main battery using the built-in charging circuit, the charging circuit, especially the transformer, It is clear that the capacity must be increased, which increases the overall size and weight of the device, which goes against the demands for smaller size and lighter weight for this type of device.

The inventor of the present invention conducted research focusing on the above problems, and found that the auxiliary battery requires less current when charging than the main battery, and that it can be charged before the battery starts to be used. Therefore, it has been found that charging can be achieved only by the input current of the inverter circuit that constitutes the charging section, without increasing the output capacity of the charging section.

This invention charges the main battery with a large capacity using the output current of the inverter circuit, and charges the auxiliary battery with a small capacity with only the input current of the inverter circuit, thereby eliminating the need to increase the output capacity of the charging circuit. It is an object of the present invention to provide a charging circuit that can effectively charge an auxiliary battery in addition to a main battery, and can complete charging of both batteries in approximately the same amount of time despite the difference in capacity between the main and auxiliary batteries. .

The present invention will be specifically described below based on embodiments shown in the drawings.

Although the drawing shows an example in which the present invention is applied to a reciprocating electric shaver, the present invention is not limited to this, and it goes without saying that the invention can be similarly applied to various small rechargeable electric appliances such as rotary electric shavers, electric hair clippers, and tape winders. be.

As shown in FIGS. 1 and 2, an electric shaver 1 embodying the present invention is provided with an outer cutter 3 that is removably attached to the upper part of a main body case 2, and an inner cutter 4 that is inscribed in the outer cutter 3. It is arranged so that it can freely move back and forth. Furthermore, inside the main body case 2, a motor 5 for reciprocating the inner cutter 4 and a rechargeable battery 6 for supplying electric power to the motor 5 are built-in, and an operation knob for a switch 7 provided on the circumferential surface of the main body case 2 is installed. In conjunction with the slide operation 11, the timing of energization of the motor 5 is regulated.

The rechargeable battery 6 is a nickel cadmium battery that can withstand multiple charging and discharging operations, and has different battery capacities, for example, an AA-type main battery 9 with a capacity of about 400 to 500 mAh, and a AA-type main battery 9 with a capacity of about 50 to 100 mAh. A set of auxiliary batteries 10 of AAA capacity is used. On the other hand, the switch 7 uses a 2-circuit, 3-contact type, so that it can be connected to the sliding operation of the operating knob 11 to switch between the first and second circuits 12 and 1.
3 contacts can be switched. That is, while connecting the primary side terminal 14 of each circuit of the switch 7 in parallel with both ends of the main and auxiliary batteries 9 and 10,
By connecting the secondary side terminals 15 to both ends of the motor 5, the motor 5 is not energized as shown in Fig. 2 when not in use, and when in normal use, for example, the operating knob 1
By sliding switch 1 one step, switch 7
The first and second circuits 12 and 13 were switched to both ends of the main battery 9 and started supplying power from the main battery 9 to the motor 5, and the main battery 9 ran out of capacity and the rotation of the motor 5 stopped. If this is confirmed, by sliding the operation knob 11 of the switch 7 one more step, the contact of the switch 7 will be connected to the main battery 9.
The power is then switched from the auxiliary battery 10 side to the auxiliary battery 10 side, and power is now supplied to the motor 5 from the auxiliary battery 10, making it possible to continue using the electric shaver 1.

The present invention provides a charging unit 16 for charging the rechargeable battery 6.
It has its characteristics.

As shown in FIGS. 1 and 2, the charging section 16
A plug blade 17 is provided at the base end of the main body case 2 so as to be freely retractable, and after full-wave rectification of a commercial AC power supply 19 inputted through the plug blade 17 in a rectifier circuit 20, an inverter circuit 21 is operated.

The inverter circuit 21 controls on/off the transistor 32 to generate an alternating current signal of approximately several tens of kHz, and applies the integrated voltage of the integrating circuit 33 to the base end of the transistor 32 through the feedback coil 34, and also applies the integrated voltage of the integrating circuit 33 to the base end of the transistor 32 through the feedback coil 34. , a coil 35 and a capacitor 36 on the primary side of the transformer 23.
are connected in parallel.

In the present invention, the auxiliary battery 10 is further connected to the input side of the inverter circuit 21, and the main battery 9 is connected to the output side. That is, the auxiliary battery 10 is interposed between the rectifier circuit 20 and the inverter circuit 21 on the negative pole side with its positive pole facing the inverter circuit 21, while the main battery 9 is interposed between the inverter circuit 21 and the rectifier circuit 20.
It is connected to both ends of a secondary coil 27 of a transformer 23, which constitutes a part of the transformer 1, via a diode 25.

With this configuration, when charging of the capacitor 37 of the integrating circuit 33 progresses, the base voltage rises, and a collector current flows to the coil 35, the current change is fed back to the base side through the feedback coil 34, and the base current increases dramatically. , and the transistor 32 is turned on instantly. Then, as shown in FIG.
A charging current flows through the auxiliary battery 10. At this time, the voltage V ₁ generated in the secondary coil 27 of the transformer 23 is
This is blocked by the diode 25 and the main battery 9 does not charge.

Next, when the feedback amount decreases and the base current decreases, the current change in the coil 35 is negatively fed back in the feedback coil 34, turning off the transistor 32 and causing the coil 3
5 generates a back electromotive force and integrates the circuit 33.
The capacitor 37 is charged to the negative side and the base voltage is kept negative to maintain the off state of the transistor 32. On the other hand, on the coil 35 side, the coil 35 and the capacitor 36 form a closed circuit, and the collector current is opposite to the collector current. A current in the direction flows through the coil 35 to complete one cycle.

Therefore, during this half-cycle period, as shown in FIG. 3b, the auxiliary battery 10 is turned off by turning off the transistor 32.
However, a positive voltage V ₂ is output to the secondary side of the transformer 23, and is applied to the main battery 9 through the diode 25, thereby charging the main battery 9.

FIG. 4 shows another embodiment of the present invention, in which the main battery 9 is connected to the inverter circuit 21 in addition to the auxiliary battery 10.
It is installed on the input side of the In this embodiment, during the half cycle when the transistor 32 is turned on, the input current of the inverter circuit 21 flows in series to the main and auxiliary batteries 9 and 10, as shown in FIG.
During the half period when the main battery 9 is turned off, as shown in Fig. 5b, the main battery 9
Charging current flows only through the battery to perform charging.

Note that the intervening position of the auxiliary battery 10 is not limited to the above-mentioned one, and can be suitably changed and implemented, such as on the positive side of the circuit or inside the rectifier circuit 20.

Although the main battery 9 is charged using only a half-cycle period of the charging voltage, other half-cycle periods can also be used for charging, or display means such as a light-emitting diode can be used to display light during this half-cycle period. A predetermined charging time may be displayed.

As described above, the present invention charges the main battery 9 with the output current of the inverter circuit 21 in substantially the same way as in the conventional case.
The auxiliary battery 10 with a small capacity is connected to the inverter circuit 2
Since charging is performed with a drive current of 1, there is no need to increase the output capacity of the inverter circuit 21, and the overall size of the device can be prevented.

Furthermore, since a sufficiently smaller charging current is passed through the auxiliary battery 10 than that of the main battery 9, the main and auxiliary batteries 9 and 9 are charged at approximately the same time despite the difference in battery capacity.
10 charges can be completed.

Furthermore, if the drive current for the inverter circuit 21 is made to flow through the main battery 9 as well, the output capacity of the inverter circuit 21 can be further reduced, and the device can be made smaller, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an example of implementing the present invention, FIG. 2 is an electric circuit diagram, and FIGS. 3 a and 3 b are explanatory diagrams showing charging conditions. FIGS. 4 and 5 show other embodiments, in which FIG. 4 is an electric circuit diagram, and FIGS. 5a and 5 are explanatory diagrams showing charging conditions. 6... Rechargeable battery, 9... Main battery, 10... Auxiliary battery, 19... Commercial AC power supply, 20... Rectifier circuit,
21...Inverter circuit, 23...Transformer.

Claims (1)

[Claims for Utility Model Registration] Rectifier circuit 20 that rectifies commercial AC power supply 19
, an inverter circuit 21 that is driven by the voltage output from the rectifier circuit 20 and outputs a charging voltage with a higher frequency than the commercial AC power supply 19 , a main battery 9 and an auxiliary battery 10 having a smaller battery capacity than the main battery 9 The above-mentioned main battery 9 is connected to the output side of the inverter circuit 21 and is mainly charged by the charging current output from the inverter circuit 21, while the above-mentioned auxiliary battery 6 is The battery 10 is connected to the inverter circuit 21
A charging circuit characterized in that the charging circuit is installed on the input side of the circuit 21 and charges only by the drive current of the circuit 21. The inverter circuit 21 described above includes a transistor 32 as a switching means, and by controlling the transistor 32 on and off, the transformer 2 connected in series with the transistor 32 is switched on and off.
Scope of Utility Model Registration Claim 1: A charging voltage for the main battery 9 is generated in the secondary coil 27 of the transformer 23 while a current is intermittently passed through the primary coil 35 and the auxiliary battery 10 of the transformer 23. Charging circuit as described. The main battery 9 and the auxiliary battery 10 described above are connected in series and interposed in the emitter circuit of the transistor 32, and both ends of the main battery 9 are connected to a diode 2 that is energized during the off period of the transistor 32.
5, the secondary coil 27 of the transformer 23
The charging circuit according to claim 2 of the utility model registration claim, which is connected to both ends of the charging circuit.